Laser is a narrow beam of Photons emitted by specially made laser diodes. Laser diode is similar to an ordinary LED, but it generates a beam of high intensity light. A laser is a device in which a number of atoms vibrate to produce a beam of radiation in which all the waves have single wavelength and are in Phase with each other.
Continue reading “Laser”
Various invasive and non invasive techniques are used for the diagnosis of diseases. Some important medical technologies are briefly described here
Continue reading “Medical Technologies”
This Pyroelecrtic Fire Alarm is one of my popular circuit published in Electronics For You Magazine December 2009 issue.The circuit exploits the direct piezo electric property of an ordinary buzzer element to sense fire. This is an unusual application of the Piezo element. This device is used in buzzer to produce sound and in transducers to generate electric signals.When the piezo crystals in the element are electrically stressed, it generates sound but if it is mechanically stressed, it generates electricity. In the circuit, it is stressed by heat and thus is act as a very good fire sensor.Full circuit in PDF.
PYROELECTRIC FIRE ALARM
Piezoelectricity is the ability of some materials such as crystals and certain ceramics, to generate an electric potential in response to applied mechanical stress or heat. If the piezo crystals are not short-circuited, the applied charge induces a voltage across the material.
Continue reading “Piezoelectricity”